Lighting

[MarkW19]

Hi guys,

I have a 10g nano tank, and it has some tropical lighting above it (around 40w), and I was wondering if the fact that it's tropical lighting over a saltwater tank, could be causing me algae problems?

I feed sparingly, with good quality food, have low phosphates, use good water, only have the lights on for a few hours each day, clean out regularly etc., and have always had algae problems.

I'm hoping it could be the lights, then at least I can try that...

 

[Ziggy953]

The lights could be part of the problem. Depending on the spectrum. Anything lower then 10,000K is going to promote "plant" growth though with readings of phosphates in the water I would say that is your biggest source.

You may want to try some phosphate remover.

Can you post your actual water parameters from your tests? What source water are you using? RO/DI?

 

[MarkW19]

Thanks for the reply...

These are the lights that I use; I have 3 of the 11w ones, 2 whites and then I've put a 9w actinic in the middle one: Arcadia - ARC-POD.

I'm running RowaPhos and have been for about 6 months, it didn't improve anything; as soon as I get the algae off it returns within about 3 days again (green hair algae all over the rocks is the main problem, not much on the glass).

When I say "low" phosphates they're classed as "barely on the scale" by my LFS...but it could be that the algae could be consuming them all, that's why they return a zero reading?

Water parameters: pH 8.2, amm 0, nit 0, nat <~3ppm, SG 1.024, temp ~27°C.

Just RO (not RO/DI).

 

[Ziggy953]

Yes I would say you are getting a false negative on your test readings. The fact that you have hair algae and occasional readings of phosphates means they are present and being consumed by the algae. Test your source water, your pure water and newly made SW and see what you get.

 

[MarkW19]

Okay will do...I'll post the results here

 

[ccCapt]

If you have the Tropical bulbs, I would say that is a large part of the problem. Just by looking at the color spectrum graph on their site, that bulb peaks in the red, orange and yellow spectrums. For a marine bulb, you want the spectrum to peak in the blue (low 400) range.

 

[MarkW19]

ccCapt: that's good to know, because I really have tried everything over the past year. I wonder if I could get some "marine" replacement bulbs for it? The actinic one I got I had to get off eBay in the US (I'm in the UK!)...

 

[ccCapt]

Can't help you there. You may be better off just buying a new small T5 fixture if you can't find bulbs.

 

[MarkW19]

I'd be prepared to get a new light fixture if it had a good chance of solving my algae problem! My tank is 10G, and the light would be fairly close to the surface...what sort of wattage would you recommend, and should it be T5?

 

[ccCapt]

I don't know the dimensions of your tank, so a T5 may not fit. But something like this would work.
Aquarium Tank Overhead White Blue T5 x3 lighting Lamp - eBay (item 220340981933 end time Jan-10-09 16:00:00 PST)

Actually, not sure if that would even work. It depends on what corals you have in there, if any. They are T5, but not HO.

These are HO, but I don't know if they will fit.
http://cgi.ebay.com/New-T5ho-t5-ho-...5|66:2|65:12|39:1|240:1318|301:0|293:2|294:50

 

[MarkW19]

Thanks a lot!! That first link looks like it will fit (not the HO one...I think HO may be too much heat for my tank anyway, and I don't have any corals at present...although I'd like to get into that in the future once my algae sorts out...).

Are those white bulbs the correct spectrum then, and will they be a bright/crisp white? Also, it's only 24w in total (inc. the actinic) - my current lights are 33w, but with these being T5 will they be a lot brighter?

 

[MarkW19]

Right, I just ordered that light, the dimensions are perfect and I've always found it hard to look for overhead lights for my tank as it's an odd size. I'm hoping the lights will be brighter than I have now, and not much heat...I'll also look at adding some decent corals too if and when I sort my algae problems out

I hope bulbs are the correct spectrum though, it didn't say...

 

[MarkW19]

Will the tubes say what kelvin rating they are?

 

[ccCapt]

They might. Some bulbs do and some don't. Probably best to ask the seller.

 

[MarkW19]

I've asked but he hasn't responded...Hong Kong though, so it's hardly surprising! Translation etc. Will see when it arrives...if there's nothing printed on the bulb, should I just compare them...if they're a brighter white than my current ones (i.e. less yellow), then they should be an improvement? Or is it more of a blue I'm looking for?

Anyway, when/if I get the algae problem sorted, I want to get a few relatively easy corals, and I've been reading a few articles about how people have successfully kept even some of the species that need a lot of light, under T5s, particularly in a small/shallow tank (my tank is only 12" deep).

I was wondering - would there be any corals you'd definitely avoid under this set-up?